This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from an application for VIDEO SHIELD FOR MONITOR earlier filed in the Korean Industrial Property Office on the 13th of February 1999 and there duly assigned Ser. No. 5278/1999.
1 . Field of the Invention
The present invention relates to a video shield for a monitor, and in particular to a video shield for a monitor, the video shield easily assembled at and disassembled from the monitor.
2. Description of the Background Art
Video shields are used in a monitor. Typically, the video shield is mounted on the electron gun of the cathode ray tube (CRT) of the monitor. The monitor is directed to display a certain character, symbol, graphic, etc., on the screen of the cathode ray tube by amplifying a video signal from a printed circuit board and emitting on electron beam from an electron gun of the cathode ray tube. Electromagnetic waves are generated from the electron gun during operation of the cathode ray tube. An external shock may cause damage to the cathode ray tube of the monitor. Therefore the video shield is sometimes used to shield the electromagnetic waves and prevent any external shock to the cathode ray tube.
We have noticed, however, that in conventional electron guns and video shield structures, a plurality of screws are used for attaching the bracket to the front casing, and a clamp is tightened with threaded fasteners. In addition, since surface tape may be attached on the outer surface of the electron gun, the assembly is complicated, and the assembly time is substantial. Moreover, conventional apparatus and techniques are not adequate to absorb and reduce the force exerted by an external shock to the election gun. Furthermore, we have found that during the process of fixing the bracket at the front casing and displaceable distal member, tightening the screws may cause damage to the election gun of the cathode ray tube.
It is an object of the present invention to provide an improved apparatus and process able to shield electromagnetic waves generated by a cathode ray tube.
It is another object to provide an apparatus and process able to prevent an external shock to an electron gun of a cathode ray tube.
It is yet another object to provide an apparatus for providing a video shield suitable for easy installation during assembly of a monitor.
It is still another object to provide an improved video shield for decreasing that decreases the assembly time of the video shield and a cathode ray tube.
It is still yet another object to provide an improved video shield able to absorb an external shock applied to an electron gun.
These and other objects may be achieved by providing a video shield for a monitor that includes a front cover, a cathode ray tube engaged to a rear surface of the front cover, and has an electron gun mounted an end portion of the cathode ray tube. The video shield unit is engaged at a rear end portion of the electron gun and includes a snap ring, a rubber collar, a front casing, a bracket, a printed circuit board with a socket, and a rear casing. The front casing includes a shaped through hole through which the electron gun passes and a plurality of snap holes formed around the through hole. The bracket that is separable from the video shield and a circular hole is formed at a portion of the front casing corresponding to the through hole and includes a plurality of displaceable distal members formed on an inner surface of the circular hole at a spaced apart from each other and protruding in a frontal direction, passing through the through hole and surrounding an outer surface of the electron gun. A plurality of snaps protrude from snap holes formed around the circular hole and engage the snap holes. The shield includes snap ring tightening the video shield at the electron gun by pressing the outer surfaces of the displaceable distal members at an outer surface of the electron gun and a rubber collar the video shield at the electron gun by generating a friction force between an outer surface of the electron gun and the inner surfaces of the displaceable distal members so that the video shield is detachable from the interiors of the displaceable distal members.